Army Spc. Jonathan Town is back home in Ohio now, but still very much at war.

"When you see bits and pieces of actual people or people bleeding to death or anything, it's very unsettling. It's something you'll never be able to forget. Period," Town told ABC News' Bob Woodruff.

Since his discharge in 2006, Town has not only dealt with the emotional scars of war, but he has also found himself at the center of a national debate on mental health care for veterans as a crowd as diverse as singer Dave Matthews and members of Congress has questioned how 22,000 veterans were diagnosed and discharged since 2001.

In Town's case, the discharge came two years after he was injured in an attack. In the fall of 2004, a 107 mm rocket ripped through his unit's headquarters in Ramadi, exploding two feet above Town's head and knocking him unconscious.

The rocket blast left Town with hearing loss, headaches, memory problems, anxiety and insomnia. For his wounds, he was awarded the Purple Heart.

But when he returned to the states seeking treatment for those very wounds, the Army quickly discharged him, asserting his problems had been caused not by the war but by a personality disorder that predated his military career.

A Quick Way Out

It is known as a "Chapter 5-13" — "separation because of personality disorder." The Army defines it as a pre-existing "maladaptive pattern of behavior of long duration" that interferes with the soldier's ability to perform his duties.

In practical terms, this diagnosis means the personality disorder existed before military service, and therefore medical care and disability payments are not the military's responsibility. But some veterans and veterans' advocates have been vocal in their belief that personality disorder is being misdiagnosed in combat veterans.

"A significant percentage of the ones who are discharged with personality disorder truly have it, but there is another percentage that are put out simply to eliminate them from military service. … It's done maliciously or as some sort of a policy," said Russell K. Terry, founder of the veterans' advocacy organization, Iraq War Veterans Organization.

Since 2001, more than 22,000 servicemen and women from all branches of the military have been separated under the personality disorder discharge, according to figures provided by the Department of Defense.

The military explained the need for this kind of discharge. "Personality disorders that interfere with military service and are incompatible with the soldier staying in the unit, it is usually best for both the soldier and the unit for that soldier to be discharged," according to Col. Elspeth Cameron Ritchie, a psychiatry consultant to the U.S. Army surgeon general.

Servicemen and women undergo mental and physical screenings when they enter the military and again before they deploy. "Either the military didn't see it or they ignored it," Terry said.

"We do histories and physicals on every recruit that comes in, but people may not always tell us everything," Ritchie said.

Veterans' Perspective

Donald Louis Schmidt of Chillicothe, Ill., was being treated for posttraumatic stress disorder after his second combat tour in Iraq. His commanders at Fort Carson later decided he was no longer mentally fit and discharged him with personality disorder.